Disposable chemical reaction packs for use in automatic analysis equipment are known in the art. Such reaction packs typically comprise a pliable body fabricated from a fluid impermeable material. The body of the reaction pack is divided into successive individual compartments or chambers that each have a blister-like configuration and are normally separated from each other with seals which are rupturable or openable in response to sufficient pressure being applied to such seals. One or more of the compartments or chambers contain predetermined amounts of reagents with which a test liquid reacts.
By applying increasing external pressure to the blister-like chambers, the normally closed seals are opened to permit transfer of the contents of one chamber to an adjacent chamber. The transfer of the test liquid between chambers and the intermixing thereof with reagents is preferably accomplished without opening the reaction pack.
Manually applying external pressure to each blister-like chamber of the reaction pack to establish sufficient internal pressure to open a normally closed seals is tedious, time consuming, inexact, and could result in damage to the reaction pack. Inconsistency or variations in pressure and time can adversely affect chemical reactions within the pack and lead to inaccurate results. It would be beneficial, therefore, to automate the process of transferring liquids through a reaction pack without requiring the reaction pack to be opened.
The liquids in the reaction pack may be subjected to temperature changes during the test procedure. It has been found, for example, that thermal cycling by heating and cooling a metal block on which a reaction pack is situated is relatively slow and inefficient. Accordingly, there is a need and desire for a device which automatically transfers liquids between chambers in a reaction pack while heating and/or cooling the liquids.